Search

CN-121974427-A - Self-floating biomass-based solar evaporator

CN121974427ACN 121974427 ACN121974427 ACN 121974427ACN-121974427-A

Abstract

The invention discloses a self-floating biomass-based solar evaporator, and belongs to the technical field of sea water desalination. According to the invention, the simplest mixing method is utilized, green and environment-friendly cellulose slurry, low-cost carbon black and the like are used for mixing to obtain a black substance which is used as a light absorption material, calcium carbonate is used as a cross-linking agent, and the black substance acts with chitosan and sodium alginate to form a skeleton structure through cross-linking, so that the aerogel has good stability, and the evaporation rate can reach 3.03 kg m ‑2 h ‑1 . And the freeze drying method is adopted to dissociate the water molecules from the aerogel with minimum damage degree, so that the aerogel has good rebound resilience and dry compression resistance, is favorable for the transportation and long-time use of materials, and effectively solves the problems of efficiency in the field of photo-thermal evaporation and realization of sustainable development with low cost.

Inventors

  • LONG ZHU
  • ZHANG CHEN
  • LI RAN
  • Xia Gewei
  • JI YILIN
  • ZHANG ZHUOFAN
  • Pan Wenkun

Assignees

  • 江南大学

Dates

Publication Date
20260505
Application Date
20260113

Claims (10)

  1. 1. A preparation method of a self-floating biomass-based solar energy evaporator is characterized by adopting chitosan, sodium alginate and cellulose to prepare hydrogel under the action of a cross-linking agent, adding black light absorbing substances and polystyrene plastic particles into the hydrogel, freeze-drying the prepared hydrogel to obtain aerogel, and cutting to obtain the self-floating biomass-based solar energy evaporator in a quadrangular frustum shape.
  2. 2. The method of claim 1, wherein the raw materials comprise, by mass, 15-25 parts of chitosan, 10-20 parts of sodium alginate, 4-6 parts of cellulose, 8-12 parts of a cross-linking agent, 3-6 parts of a black light absorbing substance and 2-4 parts of polystyrene plastic particles.
  3. 3. The method of claim 1 or 2, wherein the cellulose is from needle pulp, broadleaf pulp or cotton pulp.
  4. 4. The method of claim 1 or 2, wherein the black light absorbing material is one or more of carbon black, ferroferric oxide, carbon nanotubes, copper sulfide, graphene, black titanium dioxide.
  5. 5. The method according to claim 1 or 2, wherein the cross-linking agent is one or more of calcium carbonate, calcium chloride, calcium lactate.
  6. 6. The method according to claim 1 or 2, characterized in that it comprises in particular the following steps: s1, uniformly stirring and mixing slurry of chitosan and cellulose with water, adding black light absorbing substances, sodium alginate, a cross-linking agent and polystyrene plastic particles, uniformly stirring, standing and freezing to obtain hydrogel; S2, drying the frozen hydrogel for 24-48 hours at the temperature of minus 80 to minus 20 ℃ and the temperature of below 2 Pa, and cutting the frozen hydrogel into a quadrangular frustum shape after freeze drying to obtain the self-floating biomass-based solar evaporator.
  7. 7. The method according to claim 6, wherein the step S1 is to stir and mix the slurry of chitosan and cellulose with water for 10-20 min at 800-5000 rpm, and to stir and mix the slurry for 1-5 min at 800-5000 rpm after adding other substances.
  8. 8. The method according to claim 6, wherein the standing in the step S1 is performed at 10-30 ℃ for 20-40 min ℃ and the freezing is performed at-15 to-5 ℃ for 10-24 hours.
  9. 9. A self-floating biomass-based solar evaporator made by the method of any one of claims 1-8.
  10. 10. Use of the self-floating biomass-based solar evaporator of claim 9 in desalination of sea water.

Description

Self-floating biomass-based solar evaporator Technical Field The invention relates to a self-floating biomass-based solar evaporator, and belongs to the technical field of sea water desalination. Background Currently, the global demand for fresh water resources is increasing at an unprecedented rate. Seawater is the most abundant water resource on earth, accounting for about 97.5% of the water resource, and therefore, desalination of seawater is considered as the most powerful candidate for solving the problem of scarcity of fresh water resources. Sea water desalination is an important approach for solving the water resource shortage, and the technical development and application of the sea water desalination are widely paid attention to the international society. Among the candidate materials of the solar seawater evaporator, the biomass base stands out from the advantages of excellent inherent natural structure, easy preparation, low cost, abundant resources and the like. The biomass-based material can be used in various forms for the composition of a solar seawater evaporation system, and can be used as a light absorption material for photo-thermal conversion and a matrix material of a photo-thermal material carrier. Among them, the high-value utilization of waste biomass materials makes great sense. Aerogel materials prepared from biomass-based materials can effectively promote water transmission and evaporation due to the unique porous structure and adjustable surface wettability, and become a key material in the field of solar energy interface evaporation. For example, patent CN 117326615A discloses a three-dimensional isomerism evaporator, a preparation method and application thereof, wherein a 3D printing technology is used to prepare a new three-dimensional isomerism evaporator, a water transport layer, an evaporation water producing layer and an evaporation salt producing layer are required to be prepared first, then a 3D printing is used to prepare the water transport layer, the evaporation water producing layer and the evaporation salt producing layer in sequence, and then freeze drying and reduction treatment are performed, so as to obtain the three-dimensional isomerism evaporator. Firstly, pr-Go (partially reduced graphene oxide) ink is adopted to prepare a water transmission path layer through 3D printing, then, above the water transmission path layer, pr-Go-metal compound ink is adopted to prepare an evaporation water-producing layer through 3D printing, and then, around the evaporation water-producing layer, pr-Go-polymer ink is adopted to prepare an evaporation salt-producing layer through 3D printing. The preparation process of the invention is complicated, 3D printing and ink thereof are adopted, high cost is required, and the steps of freeze drying and reduction treatment which consume time exist, so that the large-scale preparation is greatly limited. Patent CN105460996 a discloses a capillary driven seawater desalination evaporator, the heat exchange tube bundle and the capillary layer are sintered together, the capillary layer is used as a carrier of the heat exchange tube bundle, the heat exchange tube bundle is made of materials with high thermal conductivity coefficient (including titanium, aluminum and brass), the invention has no environment-friendly and sustainable development, and in addition, the solar absorptivity and evaporation rate are lower. Therefore, there is a need to develop a self-floating biomass-based solar evaporator with simple preparation process, good mechanical properties, solar absorptivity and water evaporation rate, and high practical and economic value. Disclosure of Invention In order to solve the defects in the prior art, the invention provides a self-floating biomass-based solar evaporator. The invention prepares hydrogel by chitosan, sodium alginate, calcium carbonate and cellulose, and adds carbon black, ferroferric oxide and polystyrene plastic particles in the preparation process of the hydrogel. And freeze-drying, taking out, and cutting into a quadrangular frustum pyramid shape to obtain the self-floating biomass-based solar evaporator. The invention is realized by the following technical scheme: The first object of the invention is to provide a preparation method of a self-floating biomass-based solar energy evaporator, which comprises the steps of preparing hydrogel by chitosan, sodium alginate and cellulose under the action of a cross-linking agent, adding black light absorbing substances and polystyrene plastic particles into the hydrogel, freeze-drying the prepared hydrogel to obtain aerogel, and cutting to obtain the self-floating biomass-based solar energy evaporator in a quadrangular frustum pyramid shape. In one embodiment of the invention, the raw materials comprise, by mass, 15-25 parts of chitosan, 10-20 parts of sodium alginate, 4-6 parts of cellulose, 8-12 parts of a cross-linking agent, 3-6 parts of a black light absorbing substan